The intensity of electromotive force which generates at a generator is proportional to the intensity of magnetic field, the length of a conductor and a relative speed between the magnetic field and the conductor. The intensity of electromotive force may be increased by increasing the intensity of magnetic field or making longer the conductor or increasing faster the relative speed between the magnetic field and the conductor. It is typical that the electromotive force is increased by making faster the relative speed between the magnetic field and the conductor. For this, it needs to increase the rotational speed of the rotator, which requires a high speed rotation, so it becomes impossible to obtain a predetermined electromotive force in case where a low speed rotational force as in a tidal electric power generation, a wind power generation and a road power generation is used.
The development of a low speed generator which is able to obtain a predetermined electromotive force using a low speed rotational force is under way. One example of such a generator is disclosed in the Korean Utility Model No. 20-0217447 entitled “Low speed generator” in FIG. 5.
The low speed generator in FIG. 5 is directed to a structure wherein a high electromotive force may be obtained from a low speed rotational force in such a way that a rotor 10 and a stator 20 rotate in the opposite directions. In the above low sped generator, a fixed shaft 1 is rotatably fixed at a rotation cylinder 40, and the rotor 10 at one side of which a commutator bar 12 is disposed, is installed at the fixed shaft 1, and the cylinder stator 20 is installed at the fixed shaft 1 and is positioned at an outer side of the rotor 10. There is provided a train of gears which are configured to transfer the rotational driving force of the rotation cylinder 40 to the rotor 10 and the stator 20 in order for the rotor 10 and the stator 2 to rotate in the opposite directions.
However, in order to increase a relative speed, the above-mentioned conventional low speed generator is configured to rotate the rotor and the stator in the opposite directions by using a plurality of the trains of the gears, so the configuration of such a conventional low speed generator is complicated, and the assembling is hard, and the weight is heavy, and the manufacturing cost increases, which results in low economic feasibility.